After weeks of shooting themselves in the foot, the Phoenix were finally put out of their misery today as Sydney FC officially ended Wellington's hopes of qualifying for the A-League finals with an occasionally spiteful 4-1 win at Allianz Stadium.

The Phoenix hopes of qualifying for the six-team finals series were still a mathematical possibility when they attempted to halt a five-match winless streak at a ground they had only celebrated at once in their previous nine visits.

But a double by Alessandro Del Piero plus some killer touches and gamesmanship by the Italian master means their final regular season match against coach Ernie Merrick's previous club, Melbourne Victory, at Westpac Stadium on Saturday only has pride at stake for the New Zealanders.

Although the Phoenix have not won since a 4-1 demolition of Central Coast in late February - and have now conceded 16 goals in their last four away games - there was a sense of injustice among the team before Sydney tightened their grip on the last play-off berth.

The Phoenix were ropable when a retirement-bound Harry Kewell earned a dubious equalising penalty for the Melbourne Heart last month, and were infuriated again when the Italian went down after minimal contact with Jeremy Brockie outside the area to break the deadlock in an entertaining contest undermined by a sodden and cut up surface.

Abrasive defender Ben Sigmund was apoplectic after referee Kris Griffiths-Jones pointed to the spot and cautioned Brockie - and those frustrations were still evident after Del Piero beat Moss in the 33rd minute.

Tensions erupted in the next telling passage of play after Vedran Janjetovic spilled a Carlos Hernandez free kick and Andrew Durante and Sigmund clattered into the keeper as he regained possession.

Janjetovic and his teammates took exception to the collision, sparking a melee which culminated in bookings for Sigmund, Sydney FC defender Matthew Jurman and finally Janjetovic after Griffiths-Jones took advice from the fourth official.

A willing contest then settled down, particularly from Sydney FC's standpoint, when Del Piero eased the home side's nerves when a classic - and legitimate - curling free kick cleared the wall and thudded into the net beyond a despairing Moss in added time.

Brockie and Del Piero shook hands soon after the resumption but from then off Del Piero put the boot in - with some deft touches.

A nod on put Richard Garcia into space without reward and another teasing free kick after he was fouled by Sigmund rebounded to safety off the crossbar - a preamble to a perfect nudge for Sebastian Ryall to volley home less than a minute after Carlos Hernandez gave the Phoenix a brief glimmer of hope.

The Costa Rican, utilised for the first time by Ernie Merrick since early March due to injury and form concerns, converted a penalty after Brockie was shouldered by Nikola Petkovic.

Hernandez rushed the ball back to the centre circle, which unfortunately only sped up the concession of Ryall's stunner; Del Piero was then inevitably involved in Sydney FC's fourth although Ali Abbas deserves the kudos after teeing up the World Cup winner's deflected penalty on the left edge of the box before blasting past Moss on the hour.

To their credit Wellington contributed to a relatively free-flowing spectacle - despite the unhelpful underfoot conditions - and had All Whites goalkeeper Moss to thank for the score line not matching the 7-1 flogging they copped away to Sydney FC last season.

Del Piero scored four goals on that occasion but was contained over the dying stages - his final involvement, ironically, was being booked for diving after he went sprawling despite being out of an unsmiling Durante's reach with 20 minutes to play.